The display CSS property sets whether an element is treated as a block or inline element and the layout used for its children, such as flow layout, grid or flex.

For responsive

add -sm, -md, -lg or -xl to class name, for example:
<div class="dg-md"></div>

.dg {
    display: grid;
.df {
    display: flex;
.db {
    display: block;
.dib {
    display: inline-block;
.dt {
    display: table;
.dn {
    display: none;

See Display Grid and Display Flex